This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2000-211557, filed Jul. 12, 2000, the entire contents of which are incorporated herein by reference.
1. Field of the Invention
The present invention relates to an oral cavity spreading apparatus adapted to be used in, for example, medical examination, medical care, photographing, etc. for the interior of the oral cavity or the pharyngeal region, or oral muscle function training, or in inserting a cannula or gastrocamera into the trachea.
2. Description of the Related Art
An oral cavity spreading apparatus of this type is described in Jpn. UM Appln. KOKOKU Publication No. 56-33524, for example.
The apparatus described in Jpn. UM Appln. KOKOKU Publication No. 56-33524 comprises a pair of mouth corner hooks, left and right, which are connected to each other by means of a substantially U-shaped spring arm.
In operating this oral cavity spreading apparatus, a user first holds the left- and right-hand mouth corner hooks with his/her hand, and presses the hooks inward against the urging force of the spring arm. Thereupon, the crosswise dimension between the mouth corner hooks is reduced. Then, the narrowed mouth corner hooks are inserted into the oral cavity of a patient and hooked on the opposite corners of the mouth. Thereafter, the hand is released from the mouth corner hooks. Thereupon, the mouth corner hooks are moved away from each other to spread the mouth corners left and right by means of the restoring force of the spring arm. Thus, the interior of the oral cavity can be subjected to medical examination, medical care, photographing, etc.
Although the mouth corner hooks can be conveniently used in carrying out medical examination, medical care, photographing, etc. for the anterior tooth portions, they cannot spread alone the inner part of the oral cavity. Thus, the mouth corner hooks cannot be used for the posterior tooth portions without any problem.
Accordingly, there has recently been developed an oral cavity spreading apparatus that is provided with wing portions protruding individually outward from the respective outside portions of left- and right-hand mouth corner hooks. These wing portions serve to spread the inner part of the oral cavity, thereby widening the field of vision that leads to the posterior tooth portions.
If the wing portions are formed protruding outward from the mouth corner hooks, individually, however, the crosswise dimension between them increases, so that the wing portions hinder the apparatus from being easily inserted into the oral cavity, although they can widen the field of vision to the posterior tooth portions. Thus, the oral cavity spreading apparatus inflicts pain on the patient, and its usability for users is not satisfactory.
The present invention has been contrived in consideration of these circumstances, and its object is to provide an oral cavity spreading apparatus, which can be easily inserted into the oral cavity even though it is provided with wing portions that project outward or toward the corners of the mouth.
An oral cavity spreading apparatus according to the present invention comprises a pair of mouth corner hooks capable of being inserted into the oral cavity to spread the corners of the mouth, wing portions protruding individually outward from the mouth corner hooks and capable of spreading the inner part of the oral cavity, and a substantially U-shaped spring arm portion connecting the mouth corner hooks, the mouth corner hooks being adapted to be pressed toward each other against the urging force of the spring arm portion so that the respective end portions of the mouth corner hooks engage each other and the wing portions are steadily rotated inward and toward each other around the point of engagement between the end portions as a pivot as the mouth corner hooks are inserted into the oral cavity.
As the apparatus constructed in this manner is inserted into the oral cavity, the wing portions on the paired mouth corner hooks can be steadily kept in parallel relation, so that the crosswise dimension between them can be reduced considerably. Thus, the apparatus can be easily inserted into the oral cavity.
Further, the structure of the pivot is made small enough not to hinder the apparatus from being fitted into the oral cavity.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.